class fruit:
    color = '绿色'

    def harvest(self, color):
        print("the fruit is :" + color)
        print("The fruit has been harvested")
        print("水果原来是：" + fruit.color + "的")


class apple(fruit):
    color = 'red'

    def __init__(self):
        print("I am apple!")


class watermelon(fruit):
    color = 'yellow'

    def __init__(self):
        print("I am watermelon!")


a = apple()
a.harvest(apple.color)
w = watermelon()
w.harvest(watermelon.color)
